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Re: ctrl-c doesn't reliably kill ping

On 15/03/2016 01:45, Frank Farance wrote:
I have been having this problem with "ping".  If I "ping" a location
that doesn't exist, then "ping" just hangs and cannot be killed via
"kill -KILL [pid]".

Back to the problem, so when I type

$ ping

I do not succeed to replicate.
CTRL-C works fine for me

$ type ping
ping is hashed (/usr/bin/ping)

$ ping
PING ( 56 data bytes

---- PING Statistics----
4 packets transmitted, 0 packets received, 100.0% packet loss

or I have not a biased DNS answer.

according to "ping", the hostname resolves to (as per the
explanation above), but I cannot kill "ping".  I tried "ping" with a
limited packet size and count so, in theory, "ping" would die on its own
after 10 packets, such as:

$ ping 50 10

but it still hangs rather than timing out.  If I ping to some actual IP
address that is unresponsive (route-able to the last subnet, but dies on
the floor at the end), then I can kill via ctrl-c.  My only solution to
the hanging "ping" is to kill the terminal window.

Any suggestions on:

- Why "ping" behaves this way?
- How to avoid this problem?

Thanks, in advance.

cygwin ping is based on very old source from a time where people was not
cheating on protocol answer.
(the author passed away 16 years ago..)

can you send me a strace to see where the program is stacking ?
No promise to find a solution but I will look on it.


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